The Experts below are selected from a list of 156 Experts worldwide ranked by ideXlab platform
John A West - One of the best experts on this subject based on the ideXlab platform.
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calcium oxalate crystals in the marine red alga Spyridia filamentosa ceramiales rhodophyta
Phycologia, 2007Co-Authors: Curt M Pueschel, John A WestAbstract:Birefringent polyhedral crystals up to 8 mm on a side were found both within cells and on the thallus surfaces of several genetically distinct isolates of the red alga Spyridia filamentosa (Wulfen) Harvey. Diagnostic chemical solubility tests and silver nitrate–dithiooxamide staining identified the crystals as calcium oxalate. Calcium oxalate crystals were observed in all cell types of the vegetative erect axes: axial cells of indeterminate filaments, corticating cells of the main axes, and axial and corticating cells of the determinate lateral filaments (brachyblasts). Thalli cultured in natural seawater medium had few crystals close to the growing apices, whereas older portions of the thalli developed a surface coating of fine crystals and scattered larger extracellular and intracellular crystals. Thalli cultured in natural seawater medium whose calcium concentration was supplemented with 20 mM calcium chloride had an abundance of intracellular and extracellular calcium oxalate crystals. Thalli grown in artificial seawater medium having low calcium concentrations (1.0 and 2.5 mM calcium chloride) deposited few calcium oxalate crystals, but when these thalli were transferred to calcium-rich medium and stressed, crystals formed rapidly. The nonconstitutive nature of calcium oxalate deposition in Spyridia may explain conflicting previous accounts regarding presence of calcium oxalate crystals in this genus.
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diversity within red algal species variation in world wide samples of Spyridia filamentosa ceramiaceae and murrayella periclados rhodomelaceae using dna markers and breeding studies
European Journal of Phycology, 2002Co-Authors: Giuseppe C Zuccarello, Bernadette Sandercock, John A WestAbstract:Molecular and breeding studies on two pan-tropical marine red algae reveal vastly different levels of genetic variation and reproductive isolation. Sequenced DNA regions from the nuclear, mitochondrial and plastid genomes (partial LSU rRNA, cox2-3 spacer, RuBisCo spacer, respectively) revealed high genetic variation among individuals of Spyridia filamentosa. An rbcL analysis shows that Spyridia is a monophyletic genus distinct from other Ceramiaceae sampled, suggesting that the Ceramiaceae could be paraphyletic. There is complete congruence between all data sets of S. filamentosa, showing a well-supported phylogeographic pattern with samples from the Pacific distinct from Atlantic and Indian Ocean samples. One western Mediterranean sample is associated with Atlantic specimens, while an eastern Mediterranean sample has closer affinities to Pacific samples, possibly indicating a recent cryptic introduction into the eastern Mediterranean. Limited breeding studies imply that these samples are mostly reproduct...
Alison R Sherwood - One of the best experts on this subject based on the ideXlab platform.
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molecular and morphological variation of the red alga Spyridia filamentosa ceramiales rhodophyta in the hawaiian archipelago
Phycologia, 2012Co-Authors: Kimberly Y Conklin, Alison R SherwoodAbstract:Conklin K.Y. and Sherwood A.R. 2012. Molecular and morphological variation of the red alga Spyridia filamentosa (Ceramiales, Rhodophyta) in the Hawaiian Archipelago. Phycologia 51: 347–357. DOI: 10.2216/10-26.1 Genetic information is proving to be important in conservation and management efforts that involve cryptic species and their role in native ecosystem restoration. Previous molecular studies have demonstrated that the red alga Spyridia filamentosa consists of several cryptic species. Spyridia filamentosa is considered to be a native species in Hawai‘i and was recently used in preliminary seagrass meadow restoration efforts in Maunalua Bay, O‘ahu. It became necessary to understand the genetic diversity of this species in the Islands and determine if there are relationships between any molecular clades of S. filamentosa and anatomical characters that might be useful (e.g. sediment capture) in habitat remediation. Both molecular and morphological (determinate branch cell dimensions) analyses revealed t...
Kimberly Y Conklin - One of the best experts on this subject based on the ideXlab platform.
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molecular and morphological variation of the red alga Spyridia filamentosa ceramiales rhodophyta in the hawaiian archipelago
Phycologia, 2012Co-Authors: Kimberly Y Conklin, Alison R SherwoodAbstract:Conklin K.Y. and Sherwood A.R. 2012. Molecular and morphological variation of the red alga Spyridia filamentosa (Ceramiales, Rhodophyta) in the Hawaiian Archipelago. Phycologia 51: 347–357. DOI: 10.2216/10-26.1 Genetic information is proving to be important in conservation and management efforts that involve cryptic species and their role in native ecosystem restoration. Previous molecular studies have demonstrated that the red alga Spyridia filamentosa consists of several cryptic species. Spyridia filamentosa is considered to be a native species in Hawai‘i and was recently used in preliminary seagrass meadow restoration efforts in Maunalua Bay, O‘ahu. It became necessary to understand the genetic diversity of this species in the Islands and determine if there are relationships between any molecular clades of S. filamentosa and anatomical characters that might be useful (e.g. sediment capture) in habitat remediation. Both molecular and morphological (determinate branch cell dimensions) analyses revealed t...
David L. Ballantine - One of the best experts on this subject based on the ideXlab platform.
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Effects of culture conditions on production of antibiotically active metabolites by the marine alga Spyridia filamentosa (Ceramiaceae, Rhodophyta). I. Light
Journal of Applied Phycology, 1998Co-Authors: Pedro O. Robles Centeno, David L. BallantineAbstract:The effect of irradiance over the range 5 to 70 μmol photon m-2 s-1 on production of antibiotically active metabolites was assessed for male and female gametophytes and tetrasporophytes of the red alga Sphyridia filamentosa (Wulfen) Harvey in Hooker in culture. Whole-algal extracts and ten recognizable TLC-separable zones were assayed against five human microorganisms pathogenic to humans. For all experimental irradiance conditions, the ten TLC zones displayed activity against four of the microorganisms. The maximum number of TLC zones with activity under any of the culture conditions was six each for male and female Spyridia at 70 μmol photon m-2 s-1. Small changes in irradiance resulted both in different activities against specific microorganisms and degree of activity. The fact that every TLC zone showed differing activities at different light conditions or when extracted from different life history stages strongly suggests the presence of multiple antibiotic principals in individual TLC zones.
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Dynamics of antibacterial activity in three species of Caribbean marine algae as a function of habitat and life history
Hydrobiologia, 1996Co-Authors: Pedro O. Robles Centeno, David L. Ballantine, William H. GerwickAbstract:Antibacterial activity of lipid extracts from three species of Caribbean marine algae, Spyridia filamentosa, S. hypnoides and Wrangelia bicuspidata was evaluated monthly for one year. Activities were tested for whole plant extracts and TLC-separable zones. Whole plant extracts demonstrated monthly variability in activity with respect to both habitat and life history phase in addition to periods of similarity. No consistency was seen regarding activity against different microorganisms. TLC analyses of the extracts led to the identification of twenty-seven chromatographically distinct regions (TLC zones) each from both S. filamentosa and S. hypnoides and twenty-five from W. bicuspidata , which demonstrated antimicrobial activity. Between these species, twenty-one active TLC zones appeared to be shared based on their similar chromatographic characteristics. Individual TLC zones also demonstrated variable activity throughout the sampling period with respect to habitat and life history phase as well as periods of similarity. Algal antibiosis in these species is recognized as being highly complex, involving numerous chemical compounds, each of which is highly variable in terms of its presence and/or probable concentration.
M Govarthanan - One of the best experts on this subject based on the ideXlab platform.
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utilization of marine seaweed Spyridia filamentosa for silver nanoparticles synthesis and its clinical applications
Materials Letters, 2020Co-Authors: N Valarmathi, Fuad Ameen, A Almansob, Ponnuchamy Kumar, S Arunprakash, M GovarthananAbstract:Abstract The present study describes an environment-friendly biosynthesis of silver nanoparticles from marine red algae Spyridia filamentosa through the bio-reduction process. S. filamentosa have significantly high amounts of phytochemicals and secondary metabolites responsible for the formation of AgNPs. UV–Vis spectra results showed corresponding AgNPs peak at 420 nm. Transmission electron micrographs showed well dispersed spherical particles with the 20–30 nm in size. FT-IR and XRD results revealed the characteristics of AgNPs. Further, the AgNPs displayed potential antibacterial activity against Staphylococcus sp. (KC688883) and Klebsiella sp. (KC899845), and anticancer activity against MCF-7 cells.